Which of the following statements is true?

a. Freezing is the process bu which a gas transforms to a liquid

b. freezing is the opposite of melting.

c. freezing is the process by which liquids transform into gases.

d. freezing requires the addition of heat energy to a substance.

Which has the highest density?
a. a gram of leaves

b. a kilograms of leaves

c.a kilogram of gold

d. all have the same density

Which of the following describes a chemical property of gasoline?

a. gasoline reacts with oxygen to produce carbon dioxide and water.

b. gasoline is clear.

c. gasoline is a liquid at room temperature.

d. the density of gasoline is 0.737 g/ml


:eek:

Helpp

a. Freezing is the process bu which a gas transforms to a liquid
Think about water. If you have a gas (steam) that becomes a liquid (water), is that freezing?

b. freezing is the opposite of melting.
Think about water again. Melting goes from solid to liquid. What does freezing do?

c. freezing is the process by which liquids transform into gases.
Think about water.

d. freezing requires the addition of heat energy to a substance.
You should be able to figure out this one. Which is colder, ice (the frozen state) or water?

Which has the highest density?
a. a gram of leaves

b. a kilograms of leaves

c.a kilogram of gold

d. all have the same density

Note that these questions are trying to confuse you. A gram of leaves has the same density as a kilogram of leaves. Density is weight divided by volume. The total weight is meaningless in this context.

Which of the following describes a chemical property of gasoline?

a. gasoline reacts with oxygen to produce carbon dioxide and water.

b. gasoline is clear.

c. gasoline is a liquid at room temperature.

d. the density of gasoline is 0.737 g/ml

Have you seen gasoline? You can look up its density to determine if "d" is correct. You can also look in a gas can to see whether c or b is true. You'll have to do a little research to see if a is true. Alternately, you can eliminate three possibilities and therefore the last must be true.

For the last one, ficus on the "chemical property" part. So, I'm pretty sure all of the four answers are true.